[PATCH] i2c: qcom-cci: Fix HALT_ACK reset request being dropped

[PATCH] i2c: qcom-cci: Fix HALT_ACK reset request being dropped

[Loic Poulain]

A HALT_ACK interrupt indicates that the corresponding I2C master has
entered the halted state and must be reset before further operation.

The M0 and M1 HALT_ACK status bits may be asserted simultaneously in a
single interrupt. However, the interrupt handler currently overwrites
the reset mask when processing each HALT_ACK condition, causing the
first reset request to be lost if both events are reported together.

Accumulate reset requests instead of overwriting them so that both
masters are properly reset when M0 and M1 HALT_ACK events occur in the
same interrupt.

Fixes: e517526195de4 ("i2c: Add Qualcomm CCI I2C driver")
Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
---
 drivers/i2c/busses/i2c-qcom-cci.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-qcom-cci.c b/drivers/i2c/busses/i2c-qcom-cci.c
index 873e901a23d7a2874af5c1e738167247adff1910..bd70c6bae5dc685435bf2ad031cf7a11ec60ab4f 100644
--- a/drivers/i2c/busses/i2c-qcom-cci.c
+++ b/drivers/i2c/busses/i2c-qcom-cci.c
@@ -164,12 +164,12 @@ static irqreturn_t cci_isr(int irq, void *dev)
 	}
 
 	if (unlikely(val & CCI_IRQ_STATUS_0_I2C_M0_Q0Q1_HALT_ACK)) {
-		reset = CCI_RESET_CMD_M0_MASK;
+		reset |= CCI_RESET_CMD_M0_MASK;
 		ret = IRQ_HANDLED;
 	}
 
 	if (unlikely(val & CCI_IRQ_STATUS_0_I2C_M1_Q0Q1_HALT_ACK)) {
-		reset = CCI_RESET_CMD_M1_MASK;
+		reset |= CCI_RESET_CMD_M1_MASK;
 		ret = IRQ_HANDLED;
 	}
 

---
base-commit: ae8364085574203e7f4ea961921a1c7493bcb6de
change-id: 20261012-cci-fixes-afa0e523a2ac

Best regards,
-- 
Loic Poulain <loic.poulain@oss.qualcomm.com>

Re: [PATCH] i2c: qcom-cci: Fix HALT_ACK reset request being dropped

[Konrad Dybcio]

On 10/12/26 2:54 PM, Loic Poulain wrote:
> A HALT_ACK interrupt indicates that the corresponding I2C master has
> entered the halted state and must be reset before further operation.
> 
> The M0 and M1 HALT_ACK status bits may be asserted simultaneously in a
> single interrupt. However, the interrupt handler currently overwrites
> the reset mask when processing each HALT_ACK condition, causing the
> first reset request to be lost if both events are reported together.
> 
> Accumulate reset requests instead of overwriting them so that both
> masters are properly reset when M0 and M1 HALT_ACK events occur in the
> same interrupt.
> 
> Fixes: e517526195de4 ("i2c: Add Qualcomm CCI I2C driver")
> Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
> ---

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad